Frame Comprising A Vibration-Damping Device, Which Is Intended For The Outside Rear-View Mirror Assembly Of A Motor Vehicle

ABSTRACT

The invention relates to a frame comprising a vibration-damping device, which is intended for the outside rear-view mirror assembly of a motor vehicle. According to the invention, a moving plate bearing a mirror is connected to the inventive frame by means of a knuckle-type joint. Optionally, a case is installed on the frame in order to house a position-adjustment mechanism which is connected to the moving plate and which is actuated in order to vary the position of the plate in relation to two co-ordinate axes. According to the invention, a tab, which projects out from part of the moving plate opposite the frame, is pressed such that it can slide through a damping arrangement comprising a pair of elastic arms which form part of the frame and which extend therefrom. The aforementioned elastic arms are arranged in the form of a clamp in order to form a pressure contact against the opposing faces of the tab.

FIELD OF THE ART

The present invention relates to a frame comprising a vibration-dampingdevice which is intended for the outside rear-view mirror assembly of amotor vehicle, and more particularly to a frame which can be obtained byinjection molding and integrates a damping device forming part of saidvibration-damping device in a same part.

PRIOR STATE OF THE ART

Outside rear-view mirrors for motor vehicles comprising a frame securedto the vehicle and a moving plate to which mirror is fixed are wellknown. The moving plate is connected to said frame by means of akinematic knuckle-type joint providing it with a freedom of rotation inrelation to two mutually perpendicular axes that are generally parallelto the reflecting surface of the mirror. Both axes cross one another ata point forming the center of both rotations and which is thereforeimmobile, the joining point for joining the moving plate to the supportstructure is therefore located in said center. The rear-view mirrorgenerally includes an adjustment mechanism formed by actuation andmovement transmission means, assembled in a case supported on the framefor example. The transmission means have moving elements connected totwo points of the moving plate separated from the joining point. Anactivation of the mentioned actuation and transmission means selectivelymoves the connection points of the moving plate and thus provides itwith a swiveling movement on said two co-ordinate axes for the purposeof selecting a position adjusted to the needs of a user.

The incorporation of a damping arrangement in the form of a metallicelastic clamp fixed to the frame by means of a screw or other joiningmeans is known for the purpose of damping possible vibrationstransmitted to the moving plate, which clamp acts by securing bypressure a tab such that it can slide, which tab projects out from themoving plate. This clamp is usually a standard part on the market,manufactured in stainless steel for springs, and can be assembled bothin metal and plastic frames, whereas the tab forms part of the movingplate and is generally obtained by the injection molding of a plastic orthermoplastic material.

However, this vibration-damping device based on a metal clamp fixed tothe frame has several drawbacks. Firstly, it has a relatively higheconomic cost, given that the clamp made of stainless steel for springshas a high cost and it further involves multiple components making thestorage, logistic and assembly operations expensive. Furthermore, thesemultiple components and their assembly operation increase the risk offailures which may affect the reliability of the product. On the otherhand, the frictional contact between the clamp and the tab can cause anunpleasant metallic nose, which normally forces the application ofgrease during the assembly. Finally, the different materials of whichthe multiple parts i.e., frame, clamp, screw, etc., are made makes therecycling of the assembly at the end of its useful life difficult.

Alternatively, utility model ES-A-1054454 discloses a vibration-dampingdevice incorporating a single damping arm which forms part of a partforming the frame, and has a free end in permanent contact with asurface of a flexible tab projecting out from the moving plate. However,although this contact on a single side of the tab can neutralize mostvibration frequencies, it favors some harmonics translating into adeficient vibration damping. The material normally used formanufacturing the moving plate furthermore does not ensure theelasticity and becomes unstable over time, especially at under medium orhigh temperatures. For this reason, the result can be an insufficientdamping, which can even be nil, after a certain time of exposure of thetab to climatic factors.

EXPLANATION OF THE INVENTION

The present invention contributes to solving the previous and otherdrawbacks by providing a frame comprising a vibration-damping device,which is intended for the outside rear-view mirror assembly of a motorvehicle, said frame being of the type which is adapted to support amoving plate bearing at least one mirror, which plate is connected tothe frame by means of a knuckle-type joint allowing a combined swivelingon two co-ordinate axes, where a tab projecting out from the movingplate is pressed such that it can slide through a damping arrangementjoined to the frame for the purpose of damping vibrations. The frame ofthe present invention is characterized in that said damping arrangementcomprises at least one pair of elastic arms which form part of the frameand form a single part therewith, said elastic arms being arranged inthe form of a clamp in order to form a pressure contact against theopposing faces of said tab.

According to one embodiment, the mentioned elastic arms in the form of aclamp extend from the frame and have respective mutually opposite freeends separated by a distance less than a thickness of said tab. Theframe is suitably configured so as to be obtained by injection molding,preferably of a plastic or thermoplastic material. This construction cancover most applications, given that currently about 80% of the supportframes of rear-view mirrors of motor vehicles are carried out by moldinga plastic material. The elasticity of the arms is determined by thethickness of their cross-section in combination with the features of theselected material. The arms of the clamp can thus have a substantiallyelastic behavior whereas the frame is substantially rigid, despite beingof the same material.

The materials having suitable elasticity and climatic stability featuresfor manufacturing the inventive frame include simple materials such as,for example, PA (polyamide), PP (polypropylene), PBT (polybutyleneterephthalate), or POM (polyoxymethylene polyformaldehyde (polyacetal));or any of the previous materials including a load of FG (fiberglass forexample); or mixed materials such as for example, ABS+PC(acrylonitrile-butadiene-styrene+polycarbonate).

The frame of the present invention provides multiple advantages. Thedamping arrangement and the frame integrated in a single part provide animportant economic saving due to the reduction of components and thesubsequent elimination of the corresponding assembly operations.Furthermore, the general reliability of the rear-view mirror is thusincreased as the risk of failure due to assembly defects is eliminated.Furthermore, possible metallic noises are thus prevented and therecycling is made easier to a great extent.

BRIEF DESCRIPTION OF THE DRAWINGS

The previous and other advantages and features shall be more fullyunderstood from the following detailed description of an embodiment withreference to the attached drawings, in which:

FIG. 1 shows a partially sectioned side elevational view of a framecomprising a vibration-damping device according to the closest state ofthe art, coupled to a moving plate bearing a mirror;

FIG. 2 shows a partially sectioned side elevational view of a framecomprising a vibration-damping device according to an embodiment of thepresent invention, coupled to a moving plate bearing a mirror; and

FIG. 3 shows a plan view of the frame of FIG. 2.

DETAILED DESCRIPTION OF AN EMBODIMENT

With reference to FIG. 1, it shows a frame 21 comprising avibration-damping device, which is intended for the outside rear-viewmirror assembly of a motor vehicle, according to the state of the art.The mentioned frame 21 is adapted to support a moving plate 23 to whichthere is fixed at least one mirror 29. Said moving plate 23 is assembledby means of a knuckle-type joint allowing a combined swiveling of themoving plate 23 on two co-ordinate axes. A case is generally installedon the frame 21, which case houses an adjustment mechanism comprisingmovement transmission means connected to the moving plate 23 in order tovary its position. The case housing said adjustment mechanism and thementioned knuckle-type joint are conventional and have beenschematically shown as a whole by means of dotted lines 22 in FIG. 1.

The moving plate 23 incorporates a tab 24 projecting out from a lowerpart of such plate opposite the frame 21 for the purpose of damping apossible vibration transmission from the frame 21 to the moving plate23. Said tab 24 is adapted to be pressed such that it can slide in adamping arrangement 25 joined to the frame 1. In this frame of the stateof the art, the mentioned damping arrangement 25 comprises an elasticclamp 30 manufactured from a sheet of stainless steel for springs. Thementioned clamp 30 comprises a par of arms 31 adapted to press againstboth faces of the tab 24 and an appendage 32 through which the clamp 30is fixed to the frame 21 by means of a screw 33 or another equivalentjoining means.

FIGS. 2 and 3 shows a frame 1 comprising a vibration-damping device,which is intended for the outside rear-view mirror assembly of a motorvehicle according to the present invention, which incorporates a newdamping arrangement 5 designed to palliate some of the drawbacks of themetallic elastic clamp 30 of the state of the art, set forth above.

In a manner similar to the frame 21 of the state of the art descriedabove in relation to FIG. 1, the mentioned frame 1 according to thepresent invention is adapted to support a moving plate 3 bearing atleast one mirror 9. This moving plate 3 is connected to the frame 1 bymeans of a knuckle-type joint allowing a combined swiveling of themoving plate 3 on two co-ordinate axes. Optionally, a case can beinstalled on the frame 1, which case houses a position-adjustmentmechanism including movement transmission means connected to the movingplate in order to vary its position. The actuation of the mentionedmovement transmission means can be any of the different types that arewell known in the art of the sector. Given that the arrangement of theadjustment mechanism and of the mentioned knuckle-type joint isconventional and does not form part of the object of the presentinvention, its detailed description will be omitted and itsrepresentation will be jointly and schematically indicated by means of acase 2 in dotted lines in FIG. 2.

It must only be stated, by way of an illustrative example, that theactuation of the position-adjustment mechanism can be carried out by oneor two electric motors included in the mentioned case 2, or by one ormore electric motors located in a separate place and connected by meansof a transmission by flexible cables to the means of case 2, or bymanually operated controls connected to the means of case 2 by flexiblecables or another movement transmission. However, the adjustmentmechanism is not essential because rear-view mirror assemblies are alsoknown in which such adjustment mechanism has been omitted and in whichthe position of the moving plate 3 is directly varied manually. This isthe case, for example, of relatively large rear-view mirrors for vansand industrial vehicles in which the moving plate is simply supported bythe knuckle-type joint, in which the vibration-damping device can be adetermining factor. Therefore, the case 2 shown schematically in dottedlines of FIG. 2 is meant to indicate both a simple knuckle-type jointand a knuckle-type joint in combination with an adjustment mechanism.

Continuing with FIGS. 2 and 3, a tab 4, which projects out from a partof the moving plate 3 opposite the frame 1, is pressed such that it canslide through a damping arrangement 5 joined to the frame 1 object ofthe present invention. This damping arrangement 5 comprises at least onepair of elastic arms 6 arranged in the form of a clamp in order to forma pressure contact against the opposing faces of said tab 4. It must beemphasized that the mentioned elastic arms 6 form part of the frame 1,i.e. the frame 1 and the elastic arms 6 are formed from a single part,which is suitable configured so as to be obtained by injection molding,preferably of plastic or thermoplastic material. The elastic arms 6extend from the frame 1 to the moving plate 3 and have respectivemutually opposite free ends 7 separated by a distance less than athickness of said tab 4, such that the tab 4 causes a slight elasticdeformation of the elastic arms 6 which ensures a pressure contact. Thedegree of elasticity of the elastic arms 6 can be suitably adapted tothe requirements of its vibration-damping function by selecting across-sectional area of the elastic arms 6 according to several featuresof the material of the part forming the frame 1. The tab has a curvedconfiguration with a center of curvature substantially located at acrosspoint of the mentioned two co-ordinate axes, i.e., in the swivelingcenter of the knuckle-type joint.

According to the embodiment shown in FIGS. 2 and 3, the elastic arms 6arise from inner walls of a through hole 8 from one side of the frame 1to the other and are inclined in opposite directions converging towardssaid free ends 7, which ends gave opposite projections definingrespective contact surfaces with the tab 4.

A person skilled in the art can introduce variations and modificationsin the shown and described embodiment without departing from the scopeof the present invention as it is defined in the attached claims.

1. A frame comprising a vibration-damping device which is intended forthe outside rear-view mirror assembly of a motor vehicle, said framebeing of the type adapted to support a moving plate bearing at least onemirror and connected to the frame by means of a knuckle-type jointallowing a combined swiveling on two co-ordinate axes, in which a tabwhich projects out from the moving plate is pressed such that it canslide through a damping arrangement joined to the frame for the purposeof damping vibrations, said damping arrangement comprising at least onepair of elastic arms which form part of the frame and form a single parttherewith, said elastic arms being arranged in the form of a clamp inorder to form a pressure contact against the opposing faces of said tab.2. A frame according to claim 1, said elastic arms extend from the frameand have respective mutually opposite free ends separated by a distanceless than a thickness of said tabs.
 3. A frame according to claim 2,wherein said elastic arms are inclined in opposite directions convergingtowards said free ends.
 4. A frame according to claim 3, wherein thefree ends of the elastic arms have opposite projections definingrespective contact surfaces with the tab.
 5. A frame according to claim3, wherein the elastic arms extend from inner walls of a hole formed inthe frame.
 6. A frame according to claim 5, wherein said hole a throughhole extending from one side of the frame to the other.
 7. A frameaccording to claim 1, wherein said elastic arms have a cross-sectionalarea selected according to several features of the material of the partforming the frame to determine an elasticity of the elastic arms adaptedfor damping vibrations.
 8. A frame according to claim 1, furthercomprising a support for a case housing a position-adjustment mechanismconnected to the moving plates, said mechanism being actuated in orderto vary the position of the moving plate in relation to said co-ordinateaxes.
 9. A frame according to claim 1, wherein it is configured to beformed by injection molding.
 10. A frame according to claim 1, whereinit is configured to be formed by the injection molding of a plastic orthermoplastic material.